// 相对字体大小设置
var oHtml = document.documentElement;
getFont();
window.onresize = function () {
    getFont();
};

function getFont() {
    var screenWidth = oHtml.clientWidth;
    if (screenWidth <= 320) {
        oHtml.style.fontSize = "17.06px";
    } else if (screenWidth >= 750) {
        oHtml.style.fontSize = "40px";
    } else {
        oHtml.style.fontSize = screenWidth / (750 / 40) + "px";
    }
}